Learn about 26 of history’s raddest, equation-slinging women, such as 20th-century software inventor Grace Hopper (pictured at top right, with the rockin’ accessories), or 18th-century Frenchwoman Marie-Sophie Germain, who secretly studied mathematics at night and, under a male pseudonym, swapped ideas on number theory with mathematical greats such as Joseph-Louis Lagrange and Carl Friedrich Gauss.